1. Field of the Invention
The present invention relates to a media dispenser, and particularly, to a media thickness detecting device for a media dispenser which is able to measure the thickness of the media more precisely.
2. Description of the Background Art
FIG. 1 is a block diagram showing a general media dispenser.
The media dispenser comprises: a base plate 6 receiving a media cassette 2 where the media is stored and a collection chamber 4 for withdrawing inferior media; a media pickup portion 8 installed on a lower part of the base plate 6 for discharging the media stored in the media cassette 2 one by one; a media feeding part 10 for conveying the media discharged through the media pickup portion 8; a media discharging portion 12 for discharging the media conveyed through the media conveying portion 10 to outer part; a driving means for providing driving power required to drive the respective systems; a power transmitting means for supplying the driving power generated on the driving means to the systems; and a media withdrawing means for withdrawing inferior media during the media transmitting process.
The base plate 6 is disposed on a receiving space where the media cassette 2 is received on front side, and a receiving space where the collection chamber 4 withdrawing inferior media is received is disposed on an upper part of the above receiving space. In addition, a door 16 is mounted on front portion of the two receiving spaces.
A locking system 18 is installed on the door in order to prevent an undesignated person from accessing to the media cassette 2 and to the collection chamber 4. In addition, a cushion member 20 is installed inside the door 16 for buffing operation by adhering to a front surface of the media cassette 2.
As described above, the media cassette 2 and the collection chamber 4 are received on the front portion of the base plate 6, the door 16 is mounted on the front portion thereof to be opened/closed, and the locking system 18 is installed on the door 16 to prevent the unapproved person from accessing to the media cassette 2 and the collection chamber 4.
In addition, the cushion member 20 adhered onto the inner side surface of the door 16 absorbs the shock generated when the media is discharged from the media cassette 2.
The a power board 22 which makes the power supplied from outer part used by various electric components is mounted on a lower part of the space where the media cassette 2 is received on the base plate 6.
The driving means is a driving motor 24 which is mounted on one side of the base plate 6 for generating rotating force, and a driving pulley 26 is mounted on the driving motor 24.
The driving power transmitting means transmits the driving power generated on the driving motor 24 to respective components, the driving pulley 26 of the driving motor is connected to a passive pulley 30 by a driving belt 28 to transmit the driving power to the passive pulley 30. In addition, a timing belt 32 is wound on the passive pulley 30, a lower end connecting pulley 34 driving the media pickup portion 8 is wound on a lower end of the timing belt 32, and a discharging pulley 36 driving the media discharging portion 12 is wound on an upper end of the timing belt 32.
In addition, a plurality of tension pulleys 38 and 40 maintaining the tension of the timing belt 32 are installed on one side of the timing belt 32.
The lower end connecting pulley 34 transmits the rotating force generated by rotation of the timing belt 32 to the media pickup portion 8, and transmits the rotating force to the media conveying portion 10 as connected to the media conveying portion 10.
The media pickup portion 8 is for discharging the media stored in the media cassette 2 after dividing one by one, and comprises: a pickup roller 42 disposed on a rear portion of the media cassette 2 for discharging the media stored in the media cassette 2 downward by friction; a feed roller 44 and a dividing roller 46 disposed on a lower part of the pickup roller 42 for conveying the media discharged from the pickup roller 42 after dividing the media one by one; and a guide member 48 for guiding the media conveyed by the feed roller 44 and the dividing roller 46 toward upper direction.
The media conveying portion 10 is the portion which guides the media discharged through the media pickup portion 8 till the media discharging portion 12, and comprises a first feed belt 74 wound between a first feed roller 70 disposed on a same axis as that of the lower end connecting pulley 34 and a second feed roller 72 located on upper part; and a second feed belt 76 rotated with the first feed belt 74 as contacting to the first feed belt to convey the media.
The first feed belt 74 is wound between the first feed roller 70 which is rotated with the lower end connecting pulley 34 and the second feed roller 72 to be rotated by being transmitted the rotating force from the lower end connecting pulley 34, and guide rollers 78 and 80 guiding the moving path of the media are installed on one side of the first feed belt 74 to be rotatable.
The second feed belt 76 is rotated toward the same direction as that of the first feed belt 74 in a state that an inner side surface of the second feed belt 76 is contacted to an outer side surface of the first feed belt 74, and wound between a third feed roller 82, which is installed on a lower part of the base plate 6 to be rotatable, and a fourth feed roller 84, which is installed on a front upper part of the base plate 6 to be rotatable, and rotated.
In addition, a plurality of guide rollers 86 and 88 which guide the moving path of the second feed belt 76 are disposed on one side of the second feed belt 76.
Herein, the fourth feed roller 84 is transmitted the rotating force by gear-engaging with a gear 90 which is disposed on a same axis as that of the discharging pulley 36 on which the timing belt 32 is wound to drive the second feed belt 76.
In the above media feeding portion 10, when the driving motor 24 is operated, the timing belt 32 is rotated, and accordingly, the lower end connecting pulley 34 and the discharging pulley 36 are rotated. Then, the first feed roller 70 disposed on the same axis as that of the lower end connecting pulley 34 is rotated to rotate the first feed belt 74, and the fourth feed roller 84 gear-engaged with the discharging pulley 36 is rotated to rotate the second feed belt 76.
Then, the media discharged through the media pickup portion 8 is passes between the first feed belt 74 and the second feed belt 76, and guided to the media discharging portion 12.
The media discharging portion 12 discharges the media conveyed from the media feeding portion 10 in order to transfer the media to the user, and comprises: a first discharging roller 98 installed on a same axis as that of the discharging pulley 36 and rotated with it; and a second discharging roller 100 connected to the first discharging roller 98 through a discharging belt 102 and rotated. In addition, the discharging belt 102 is rotated toward same direction as that of the second feed belt 76 in the status of contacting to upper part of the second feed belt 76 to discharge the media to outer side.
The media withdrawing means is for withdrawing media in cassette that an error is generated or two pieces are conveyed at one time during the media is conveyed through the media feeding portion 10, and comprises a connection chamber 4 disposed on the upper part of the media cassette 2 for storing inferior media and a diverter 104 installed between the first feed belt 74 and the discharging belt 102 for withdrawing the inferior media into the collection chamber.
In addition, the media dispenser comprises: a feed sensor 92 installed on one side of the media feeding portion 10 for counting the media by sensing the media passage; a thickness detecting device 94 for detecting the thickness of the media; an eject sensor 106 for sensing the media discharged through the media discharging portion 12; a reject sensor 108 installed on the collection chamber 4 for counting the inferior media which is withdrawn; and a slit sensor 96 for sensing the rotating times of the driving motor 24 and length of the media with the feed sensor 92 to control the operations of the media dispenser.
FIG. 2 is a side view showing a media thickness detecting device of the media dispenser according to the conventional art, and FIG. 3 is a front view showing the media thickness detecting device of the media dispenser according to the conventional art. The media thickness detecting device shown in FIGS. 2 and 3 senses the overlapped media by detecting the thickness of the media, and FIGS. 2 and 3 are views showing an expanded part of the media thickness detecting device shown in FIG. 1 required by the present invention.
The media thickness detecting device according to the conventional art comprises: a feed roller 120 disposed on a same axis as that of the guide roller 80 which guides the first feed belt 74 and through which the media passes; and a thickness detecting sensor 122 surface contacted to the feed roller 120 to detect the thickness of the media 140 passing the feed roller 120 and thereby sensing the overlapped media.
The thickness detecting sensor 122 comprises: a sensing roller 124 contacted to the feed roller 120 and rotated with the feed roller 120; a rotating arm 126, to which the sensing roller 124 is mounted to be rotatable, having one side connected to a hinge shaft and rotated; and a thickness measuring portion 130 installed on the other end of the rotating arm 126 for detecting rotating times of the rotating arm 126 to measure the thickness of the media.
The sensing roller 124 is formed as a cylinder having a predetermined thickness and an outer circumferential surface of the sensing roller 124 is surface-contacted to the surface of the feed roller 120. In addition, the sensing roller 124 is mounted on an axis 132 which is connected to one side of the rotating arm 126 to be rotatable.
According to the media thickness detecting device of the conventional art, when the media passes between the feed roller 120 and the sensing roller 124, the sensing roller 124 is moved as much as the thickness of the media 140. And according to the movement of the sensing roller 124, the rotating arm 126 is rotated as centering around the hinge shaft 128 and the thickness measuring portion 130 installed on the other end of the rotating arm 126 detects the rotating amount of the rotating arm 126 to measure the thickness of the media 140.
However, in the media thickness detecting device according to the conventional art, the axis of the feed roller 120 and the axis of the sensing roller 124 should maintain the parallel status in order to detect the thickness of the media precisely. That is, the circumferential surfaces of the feed roller 120 and of the sensing roller 124 should be contacted in parallel direction with each other and maintained the ling contacting status in order to detect the precise thickness of the media. However, the angle of the axis of the feed roller 120 or of the sensing roller 124 can be changed to some degree in the assembly process or under actual usage environment due to the load, etc., and according to the change of the axis angle, the feed roller 120 and the sensing roller can not be contacted ideally. Then, the change of axis angle is deepened such that the points are contacted or edges of the rollers are contacted, or the distance is changed. Consequently, a tolerance of media thickness sensing is exceeded.